Numerous methods and patents are known which relate to the transfer and fixing of toner images and in some cases the encapsulation of those images as part of a process of electrography. One of those patents, U.S. Pat. No. 4,337,303 discloses a method for the development, transfer, encapsulation and fixing of a partially dried liquid toner image in an electrographic process. This method can be utilized only within an electrographic process under precise, limited conditions and cannot be employed to transfer and/or encapsulate, dried fixed images.
Other known processes by which words, symbols or art work can be transferred are limited to existing or predetermined symbols, words or other images and/or are extremely tedious and impractical. An example of a previous image transfer method utilizes so called dry transfer images. Basically these consist of individual letters and/or symbols with an adhesive backing which must be individually removed from a sheet containing many such letters or symbols and placed in the order and position desired. In order to produce a variety of signs, labels or the like, it is necessary to maintain large quantities of redundant characters and often a particular letter or symbol is not in stock even though a great quantity of materials are in inventory. Combinations of letters and symbols are also available but they must necessarily be limited in choice and number. The above products are usually available only in black or a very limited choice of colors. In addition, the work is tedious and the quality of the finished product depends on the skill of the person performing the work.
Another prior art system for transferring images is a wet process designed to transfer existing images from clay-coated papers. In that process an adhesive transfer film is applied to the image to be released and the assembly soaked in water. The softened paper is disintegrated to remove it from the adhesive film leaving the image on the film which can then be adhered to a new substrate to position and encapsulate the image. Problems with this technique are the time-consuming and messy operations of first soaking the complex in water for several minutes, then physically destroying the substrate by rubbing it off in pieces from the image-carrying transfer film. Finally, the debris must be cleaned up and the transfer film allowed to dry before it can be applied to a surface.
On the other hand the present invention requires no inventory of pre-formed symbols, can be used with virtually any form of image, and can be employed to produce composites, combinations and alternative forms, can create images in a variety of colors and may be employed without destroying or damaging the original. Another important advantage of the present invention over prior methods is that the original substrate sheet remains intact after images have been removed for transfer. This means that standard size sheets, such as loose-leaf sheets in a ring binder, can be used to inventory and selectively dispense images such as address labels without being cut up or otherwise destroyed in the transfer process. Unlike the wet process, the present invention does not expose the adhesive coating of the transfer film to water or to the abrasive action of direct rubbing to remove substrate particles.
This invention is applicable to any fixed image which is in a form that can be separated from the substrate on which it is carried or which can be reproduced in a form that can be separated from its substrate. Toner images which have been produced by electrography are desirable because they produce an excellent image when transferred and because of the great flexibility of the image which can be produced. It is possible also, when the original image is not separable from its substrate, or when it is desirable to preserve it, to produce an intermediate toner image by electrography from the original and then transfer and encapsulate the toner image as disclosed herein. Electrographically produced images also have the advantage of being duplicable in almost any number from a single original without destroying or harming the original, of being produced in black and white or color images and of being produced from a wide variety of two or even three dimensional images in a form which can be readily transferred in accordance with this invention. Electrography also provides a means of combining preexisting images into a composite or modified image which can then be utilized in the present process.
In the method of this invention it is desirable that an image to be transferred from one substrate to another be carried initially on a substrate from which it is readily separable. For this reason also electrographically produced images are desirable because they can be produced on image-releasing sheets from which they can be easily lifted by a transfer medium for transfer to a final substrate and encapsulation. Various paints, marking inks and other marking materials are available and suitable to produce a transferable image. It is possible also to add three dimensional objects which may be employed to produce collages.
The substrate from which the image is to be taken is preferably a material which will readily release the image to a transfer medium or laminator described below, which is employed to separate the image from its initial substrate and to transfer it to the final substrate. The transfer medium also serves as the laminator or encapsulating material, attaching the image to the final substrate and providing a protective cover over it. This transfer medium is preferably an adhesive material or a material provided with an adhesive coating which will adhere to the image to be transferred but which will separate readily from the initial substrate. For effective image transfer, the bond between the image and the adhesive on the transfer film must be stronger than the bond between the image and the initial substrate. The transfer medium should also be highly transparent and have good abrasion resistance and other characteristics which make it suitable for encapsulating the image in its position on the final substrate.
Xerographically produced toner images are good examples of the type of image suitable for transfer by the method disclosed. It is preferable that the toner image produced in the xerographic process for transfer according to this invention be produced on a suitable image-releasing sheet, several types of which are readily available. Smooth polyester films or similar products are suitable image-releasing substrates. A suitable transfer medium may be found among any of various transparent adhesive films or tapes. Those which have an adhesive that will readily adhere to a variety of surfaces, but which are removable without destroying the film or adhesive coating or the original image releasing substrate are preferable. As indicated above, the film should also have the desired transparency and abrasion resistance which will make it a good laminator.
The target image or image to be transferred and encapsulated is painted, printed or copied or otherwise applied by machine or manually to an image-releasing substrate. The adhesive side of an adhesive film or tape is applied over the image and lightly burnished to insure adhesion of the image to the adhesive coating on the film. The adhesive film with the image adhered to it is then lifted from the image-releasing substrate, separating the image from the substrate. The adhesive film and image are moved into position over the surface of the final substrate and the film is applied to the surface with the image in the desired position. The adhesive film is pressed onto the final substrate encapsulating the image in its desired position.
It is preferable that the transfer image remain physically discrete when formed on the releasing substrate, meaning that it is not absorbed or otherwise permanently bonded with the initial substrate and can be separated from the substrate by use of an adhesive film as herein described. One advantage of this invention is that images which have little cohesive integrity apart from the substrate which hold them are reserved intact when separated from their substrate by the transfer film. Of course, these properties will be affected in part by the ease with which the image can be released from the substrate. A fixed toner image has suitable characteristics, but images comprised of paint, resins, plastics or other materials may also be used. Furthermore, the images may be produced by typing, printing or electrography or may be manually drawn or printed or produced by any other means. This makes the process extremely versatile.
It can be seen that the method is applicable to a wide variety of images of various types produced by a wide variety of methods including machine or manual drawing and permits the transfer of these images to a wide variety of surfaces. In addition to the great versatility of the system, it is found that encapsulation of an image with a transparent film produces visual enhancement of the image as well as protection from abrasion and other damage.
It is an object of this invention to provide a method of transferring an image from an initial substrate to a desired final substrate.
It is another object of this invention to provide such a method employing known and readily available materials and means.
Still another object of this invention is to provide a method of transferring an image from an initial substrate to another substrate which method is extremely versatile and suitable for use with a wide variety of types and forms of images.
These and other objects, features and advantages of this invention will become apparent from the following description in conjunction with the accompanying drawings. The process by which the image to be transferred is created is not a part of this invention nor is this invention limited by the process by which such image was formed.